GB600118A - Improvements in or relating to the catalytic oxidation of hydrogen sulphide in gaseous mixtures - Google Patents

Abstract

Gaseous mixtures, e.g. coal or fuel gas, are contacted in the presence of oxygen with a single solid catalyst mass comprising a sulphide or sulphides of nickel or cobalt at a temperature not exceeding 80 DEG C., but preferably above the dew point of the mixture, to oxidize the hydrogen sulphide content to sulphur. The process may be used to remove either hydrogen sulphide or oxygen. High humidity, e.g. 80-100 per cent of saturation and the addition of ammonia assist the reaction. Low temperatures and oxygen concentration reduce the tendency to side reactions leading to sulphur oxides. In examples, nickel or cobalt hydroxide or basic carbonate are treated with hydrogen sulphide at 100 DEG C. to produce the catalysts and temperatures of 25-27 DEG C. are used for the catalysis. Catalyst poisoned by sulphur or sulphate may be regenerated with a solvent, e.g. carbon disulphide, aromatic hydrocarbons or preferably ammonium sulphide or by removal of sulphur by evaporation or conversion, e.g. with hydrogen, to a gaseous compound. Oxygen may be added to the gas or adsorbed, e.g. from air on the catalyst prior to reaction, which allows countercurrent operation. According to the Provisional Specification, temperatures up to 250 DEG C. may be used, the catalysts may be produced by precipitation or by reduction of sulphates and may be used in gaseous suspension, on a carrier, or as a broken cake. Specifications 241,221, [Class 38 (v)], and 276,347, [Class 1 (i)], are referred to.